Ammonium salt



' Patented Nov. 30, 1926.

EDWARD WILLIAM HARVEY, OF NEW BRUNSWICK, NEW JERSEY.

Ammon um SALT.

No Drawing, Application filed August 16. 1922, Serial No. 582,134.

My invention relatesvto drying and im:

proving the physical condition of ammon1-.

um salts by lowering the percentage of free acid and free moisture contained therein. 5 In" the production of ammonium sulfate by the usual processes, as for example as a by-product from illuminating gas manufacture and coke Works, or when ammonia has been obtained directly from the air synthetically, it has been customary to pass the gases containing ammonia through a saturator bath of sulfuric acid solution Whereupon the ammonium sulfate is formed and is precipitated when the reaches the proper amount. These crystals are collected and the surplus liquor is drained off or removed in the centrifugal. Some of the acid mot-her liquor clings to the surfaces of the crystals; Tlie bulk of the moisture can be removed Without great ditiiculty, but even a very small residue of the same is objectionable. The removal of these last small amounts of acid and water is very difficult. Ammonium sulfate in such a condition, containing some free acid and free moisture, is difiicult to handle, ship and use because of its poor physical condition and the tendency of the free acid to retain and absorb moisture and to destroy the fiber of the bags in which it may be contained.

By my invention much or all of the free acid of the ammonium sulfate is neutral ized, or a sulfate is formed therefrom, and

v 3 much or all of the free moisture of the arm monium sulfate is changed from the free state to a chemically combined state by' the addition of one or more materials for this purpose. It is preferable to add a ma- 4U, terial which is itself a fertilizer and which will at the same timeiovercome the deleterious properties of the impure ammonium sulfate.

In practicing this invention I may add 453 tothe ammonium sulfate as usually repared a mixture of hemi-hydrate of calcium sulfate (CaS0,) gH O, calcium 'oxide (CaO), calcium hydroxide [Ca(O I-I) and calcium carbonate (CaCO or I mayadd so one or more of these in suitablev proportion, or I may add a suitable commercial product containing among its several ingredients hemi-hydrate of calcium sulfate and a basic material or materials, as calciu5 um oxide or calcium hydroxide, such a commercial product being commonly known concentrationv monium sulfate crystals, as the crystals are HEISSUED Renewed Qctober 5, 1925. c

as stucco" or plaster of Paris; All of the above materials used as additions are to be added in a finely divided or powdered state. The action of such additions to ammonium 5U sulfate has the following effect.

First, the bases neutralize the free acid and absorb some moisture, according to the formulee cao+iuso,+u,ozo so erno Second, the hemi-hydrate of calcium sulfate (CaSOQ H O dries the mixture by combining with the free moisture contained in the mixture. in accordance with the foli5 lowing formula (Casog,n oa-su oze case no).

vary from a fraction of 1 per cent to 10 per cent of the ammonium sulfate to be treated, depending upon the amount of free sulfuric acid and free Water in the ammonium sulfate.

Ammonium sulfate treated as above described has been found to be greatly benefited as to physical condition after such treatment and is much more satisfactory. The ammonium sulfatemay be mixed=with the finely divided material in any convem ient way or the material may be blown or otherwise applied as a dust over the am agitated or the mass is rolled, or the mix-1 ture of the ammonium sulfate and the material to be added may be effected in any other convenient Way. v 7

While the invention has been specifically described in connection with ammonium sul-' fate, 1t 15 also applicable to the treatment T of ammonium chloride for the purpose of improving its physical condition and producing a more desirable product.

I claim- 1. The process of improving the condition of commercial ammonium sulfate, which comprises adding thereto a mixture comprisinga material containing a basic cal- ,cium. compound," and hemi-hydrate of calcium sulfate.

2. The process of improving the condition of commercial .ammonium sulfate, which comprises adding plaster of Paris thereto.

3. The process of improving the condition of commercial ammonium sulfate, which basic material in amount insufficient to decompose an appreciable quantity of the ammonium sulfate. 1

5. The process of drying and improving the physical condition of ammonium sulfate which comprises adding thereto a material containing powdered plaster of Paris.

6. The process of drying, neutralizing and improving'the physical condition of ammonium sulfate which comprises addin thereto a material containing powdered hemihydrate of calcium sulfate and basic material.

7. The process set forth in claim .5, in

which the material is added to the ammonium sulfate by blowing'it thereon.

8. The process set forth in claim 6, in which the material is added to the ammonium sulfate by blowing it thereon.

In testimony whereof I hereto ailix' my signature.

EDWARD WILLIAM HARVEY. 

